I would like to suggest BEFORE you waste any clearing efforts and your hard earned money, get a PH Test! You can't go in ANY direction until you know IF your soil can grow the seeds you want. Once the PH is known it's then simply up to you to apply the proper amount of lime and/or fertilizer to allow the ground to release it's nutrients and not bind it.

That being said, for a Fall plot I would suggest something like a Oats/Wheat/Brassica blend. These seeds are super easy to plant/broadcast and feature explosive growth so you'll have a successful plot in record time.